Association of serum interleukin-6 and soluble interleukin-2-receptor levels with disease activity status in patients with inflammatory bowel disease: A prospective observational study.

Eirini Mavropoulou,Golo Petzold,Yiannis Pilavakis,Volker Ellenrieder,Ahmad Amanzada,Nicolae-Catalin Mechie,Richard Knoop,Steffen Kunsch,Bruno Bonaz

doi:10.1371/journal.pone.0233811

Abstract

Crohn’s disease (CD) and ulcerative colitis (UC) are characterized by overexpression of proinflammatory cytokines. We determined the association of serum levels of interleukin (IL)-6, soluble-IL-2-receptor (sIL-2R) and CRP as well as of faecal calprotectin (FC) values with disease activity in CD and UC patients. This prospective study included 145 CD and 84 UC patients. Serum proinflammatory biomarkers and FC levels were measured and demographic, clinical and endoscopic characteristics were collected. Uni- and multivariate statistical analyses were performed. Serum IL-6 and CRP levels as well as FC values of CD patients were associated with clinical and endoscopic remission. In multivariate analysis serum IL-6 levels remained significantly associated with clinical and endoscopic remission. FC levels were also associated with endoscopic remission in CD patients. CD patients under the threshold levels of 8.5 pg/mL and 5.5 pg/mL for serum IL-6 were in 70% and 66% in clinical and endoscopic remission, respectively. Serum sIL-2R, CRP levels and FC values of UC patients were associated in univariate analysis with clinical and endoscopic remission. In multivariate analysis CRP and FC values were associated with clinical remission and serum sIL-2R as well as FC levels with endoscopic remission. UC patients under the threshold levels of 759 IU/mL and 646 IU/mL for serum sIL-2R were in 76% and 76% in clinical and endoscopic remission, respectively. Beside CRP and FC, serum IL-6 levels in CD patients and sIL-2R levels in UC patients can be a further useful non-invasive biomarker to identify the disease activity status.

Highlights

Inflammatory bowel diseases (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC) are chronic diseases of unknown etiology
More CD patients smoked than UC patients (p = 0.01)
In regard to sIL-2R and faecal calprotectin (FC) levels there were no significant differences between the two IBD cohorts. 54% were on monotherapy and 21% had a combination therapy. 63% were in clinical remission and 49% (75/153) were in endoscopic remission

Summary

Introduction

Inflammatory bowel diseases (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC) are chronic diseases of unknown etiology. Response to intestinal microbiom in genetically susceptible individuals is proposed as a pathogenic mechanism underlying IBD [1]. Both diseases are characterized by a relapsing chronic inflammation resulting in mucosal injury affecting the gastrointestinal tract [2]. Various proinflammatory cytokines are currently known to play an important role in the pathogenesis of IBD [3]. Cytokines such as interleukin-6 (IL-6) and soluble IL-2 receptor (sIL2R) have been shown to modulate the intestinal immune system by increasing the expression of adhesion factors on endothelial cells enabling transmigration of phagocytes and lymphocytes to sites of inflammation. CRP is one of the best-studied inflammatory parameters in IBD patients

Methods

Results

Conclusion